Hi ! Everyone...
Acctaully I want to know what is theory apply for telebid.com about their time counter in home page. Can any one describe ?

No. 2 - How can I send automatic email ?

If you are talking about the page it redirects to (http://www.swoopo.co.uk/) then my answer is as below:
As for the counters, Ajax or Java would have been used for the live changes (since the countdown counts up a bit when someone bids & displays a red box when someone bids). So php isn't really used in this case. Also one way for doing the live updates which with that many bids may cause a bit of a high server load is for each bid, a mysql entry is updated saying what the new bid is and updates the mysql time to something like time+2 seconds. But one thing that will save a bit of server load is instead of every second updating the time in the database, Java/Ajax updates the time in the database whenever a bid is placed and the user end updates the countdown locally every second. Then you may think what about those who just entered the page who haven't got an accurate reading of how much time is left. Well on the same row as the number of seconds left would be another column in the database for when it was last updated. So the computer can subtract the current time from the last updated time then subtract the answer from the time remaining as shown in the database which then provides the latest timing of the item for the computer to locally count down. That's the theory (and in Java/Ajax not php)